The North Group Roses game was scheduled for a 6.15pm start and Yorkshire announced on Twitter that the quartet, including David Willey and Tom Kohler-Cadmore, will not take part.
Yorkshire said: “Matthew Fisher, Tom Kohler-Cadmore, Josh Poysden and David Willey have been withdrawn from tonight’s squad in accordance with COVID guidance.
“The club are awaiting results of a COVID test which will determine future availability.”
Yorkshire are bidding for their third Vitality Blast win of the season in a bid to keep their hopes of qualifying for the quarter-finals alive.
Willey and Kohler-Cadmore have both captained the side in the competition this season, while Fisher (eight wickets), Willey and Poysden (both five) are the county’s three leading wicket-takers.
Lancashire are currently second in the table having lost only one of their first four matches.
Yorkshire batted first and made 145-9 from their 20 overs, Adam Lyth top-scoring with 36 from 20 balls while England international Dawid Malan added 27.